Regarding Wrapper class objects

Question

I know that we've to use equals() method in place of '==' to compare two objects. but some one pls explain me how the following code snippet works. Is here anything is related to auto boxing?
Integer j1 = 127;
Integer j2 = 127;
System.out.println( j1==j2); //Works!!!
Integer k1 = 128;
Integer k2 = 128;
System.out.println( k1==k2); //Doesn't Work!!!
Integer w1 = -128;
Integer w2 = -128;
System.out.println( w1==w2); //Works!!!
Integer m1 = -129;
Integer m2 = -129;
System.out.println( m1==m2); //Doesn't Work!!!

Answer 1

Diablo_Chiru wrote:
yeah i know that thing but i don't know why it is
giving the correct result for these two?
System.out.println( j1==j2); //Works!!!
System.out.println( w1==w2); //Works!!!and contradicing result for the following?
System.out.println( m1==m2); //Doesn't Work!!!
System.out.println( k1==k2); //Doesn't Work!!!can u expain it in details ? pls
DiabloI tried to avoid answering that since you the get VM dependent. The documentation says that some values might be cached, and values in the range -128 to 127 must be cached according to the specification. Other values can also be cached, so your later comparisions might return true in the future.
Kaj